SUSTAINABILITY is no piddling matter for environmental guru Joost Bakker.

As part of this year's Melbourne Food and Wine Festival next month, Joost, who has turned waste saving into an art form, is planning to create a restaurant where the stoves and ovens are run on power generated from mustard seed oil.

Not much wrong with that, until we tell you the eatery's patrons will also contribute to sustainability by supplying the fertiliser to grow future mustard oil supplies.

The restaurant's specially designed toilets will harvest the patrons' nitrogen-rich urine, which will then be trucked to a Daylesford farm and applied to a crop of mustard to complete the circle. Could this be taking recycling a wee bit far?